Hi Ken!
I know that cleaning tools are no magical thing but since lot of software developers make lame uninstallers it’s nice to keep things at least a bit clean, especially the registry.
CCleaner doesn’t clean normal Windows Firewall items (better not) so I think there is something wrong the way Glasswire uses the API that makes the entry invalid. Since CCleaner is the most used cleaner (and doesn’t have the reputation of cleaning too much) I think it would be worth it to take a look at it.
For example these are 3 firewall rules in my registry. Only the top one is an ‘invalid Firewall rule’ created by Glasswire.
v2.31|Action=Allow|Active=TRUE|Dir=Out|App=c:\nvidia\displaydriver\497.09\win11_win10-dch_64\international\setup.exe|Name={GlassWire.out.app_-1568807406.profile_1.mode_1}|Desc=GlassWire|EmbedCtxt=GlassWire|
v2.31|Action=Allow|Active=TRUE|Dir=In|App=C:\Program Files\Blackmagic Design\Fusion 17\FuScript.exe|Name=Blackmagic Fusion FuScript Services|Edge=TRUE|
v2.31|Action=Allow|Active=TRUE|Dir=In|Profile=Domain|Profile=Private|Name=@{Microsoft.Todos_0.57.43142.0_x64__8wekyb3d8bbwe?ms-resource://Microsoft.Todos/Resources/app_name_ms_todo}|Desc=@{Microsoft.Todos_0.57.43142.0_x64__8wekyb3d8bbwe?ms-resource://Microsoft.Todos/Resources/app_name_ms_todo}|LUOwn=S-1-5-21-3304635862-234857484-550727902-1001|AppPkgId=S-1-15-2-2537927067-2140208811-1083047336-3825492100-1188134376-3459723148-3131426163|EmbedCtxt=@{Microsoft.Todos_0.57.43142.0_x64__8wekyb3d8bbwe?ms-resource://Microsoft.Todos/Resources/app_name_ms_todo}|Platform=2:6:2|Platform2=GTEQ|
So I wondered why the bottom two are ok but the top one is not. Maybe it has something to do with the name given by GlassWire and the {} it uses.

No other rule in Windows Firewall has those {} (what was the English word?) around their name. So I can imagine it already works if the name would be GlassWire-Out-Profile-1 for example.
It’s just a suggestion and maybe easy to fix. I don’t know if the rules are actually invalid or CCleaner just doesn’t like those { } in their names. But must say I can imagine they can cause conflicts, also with other programs since you may not use them as a name normally.
Kind regards and keep up the good work!